Considerable work has been done on the chemistry of 3-substituted-1,2,5-thiadiazole compounds. See for example, Horning et al. Canadian Journal of Chemistry 51 2349 (1973) and Deyrup et al. Journal of Organic Chemistry 42 1015 (1977). However, little work has been done on 2-substituted-1,2,5-thiadiazoles of the type shown for example in Rockach et al., Journal of Organic Chemistry 44 1118 (1979).